It is known to construct sheeting material from laminated layers of plastic film, such as polyethylene or polyvinylchloride, having cells of air trapped inside. One application of such sheeting materials has been as coverings for swimming pools.
Examples of disclosures incorporating such structures are found in the following documents:
U.S. Pat. No. 3,072,920 to J. I. Yellott PA1 U.S. Pat. No. 4,028,750 to Erik G. Gustafsson PA1 U.S. Pat. No. 4,313,421 to John M. Trihey PA1 U.S. Pat. No. 4,146,015 to Loren C. Acker PA1 U.S. Pat. No. 4,197,595 to LeRoy M. Dearing PA1 U.K. Appln. No. 2,025,602 to Allan William Taylor PA1 FGR Offenlegungsschrift No. 2,212,413 to Franz Kerner PA1 FGR Offenlegungsschrift No. 2,149,851 to Franz Kerner PA1 Japanese No. 56-168061 to Kiyoshi Horie.
In all of the foregoing cases air is sealed in chambers within successive layers of sheeting.
It has also been proposed to improve the solar absorption of swimming pools by floating absorption chambers over the top surface of a pool and pumping water therethrough.
Covers of both classes are bulky to roll-up for purposes of storage. Because they are composed of multiple layers of sheeting bonded together, they require complicated fabrication techniques.
It is therefore an object of this invention to provide sheeting which may be more easily fabricated and has the feature of being more easily compressed for storage. It is a further feature of this invention to adapt the foregoing sheeting material to form a continuous chamber through which a liquid may be circulated as a means of absorbing solar energy.